Question

I. Daska is situated at a distance of 15 miles from both Gujranwala and Sialkot. A bus travels from Gujranwala to Daska at an average speed of 25 miles per hour, from Daska to Sialkot at an average speed of 40 miles per hour and returns to Daska at an average speed of 30 miles per hour. Find the average speed for the entire trip.

Answer 1

The average speed of the entire trip is 8.5 miles per hour.

Explanation:

Speed = Total Distance / Total Time

So we have to find the total distance and the total time taken .

1) From Gujranwala to Daska

speed= 25miles/hour distance = 15miles

Time taken = distance / speed

= 15/25= 0.6 hours

2) From Daska to Sialkot

speed= 40miles/hour distance = 15miles

Time taken = distance / speed

= 40/15= 2.67 hours

3 ) From Sialkot to Daska

speed= 30miles/hour distance = 15miles

Time taken = distance / speed

= 30/15= 2 hours

The total distance traveled to three places is = 15+ 15+15= 45miles

The Total time taken is = 0.6+ 2.67+ 2= 5.267=5.3 hours

Speed = Total Distance / Total Time

Speed= 45/ 5.3

= 8.49=8.5 miles per hour

The average speed of the entire trip is 8.5 miles per hour.